Chemical profile and cytotoxic activity of a polyphenolic-rich fraction from Euphorbia dendroides aerial parts.

• The first extensive study of the polyphenolic profile from Euphorbia dendroides aerial parts growing in Egypt. • The phenolic compounds constitute the phenolic-rich fraction of plant were tentatively identified using LC-ESI-MS/MS. • The extensive chromatographic purification of this fraction led to the isolation and identification of seven known compounds for the first time from the plant under investigation. • The phenolic-rich fraction of the plant and its active constituent could be potentially helpful in the management of ovary and breast cancer. Taking into account the great interest of Euphorbia plants as potential sources of active phytochemicals, this study aims to investigate the polyphenols of Euphorbia dendroides aerial parts in relation to its cytotoxic activity. the total phenolic and flavonoid contents of E. dendroides aerial parts were determined as 152.2 ± 10.16 mg GAE/g DW and 66.68 ± 4.46 mg RE/g DW, respectively. Polyphenolic-rich fraction (EdPh-B) was chromatographically fractionated from the hydro-ethanolic extract of this plant. LC-ESI-MS/MS analysis of EdPh-B showed the presence of three phenolic acids and five flavonoids. Additionally, the extensive chromatographic purification of EdPh-B resulted in identified of seven known compounds; vanillin (1), luteolin (2), quercetin-3- O - β - d -glucuronopyranoside (3), kaempferol-3- O - β - d -glucuronopyranoside (4), gallic acid (5), trans -caffeic acid (6) and protocatechuic acid (7), which are first reported from the plant. Moreover, in vitro cytotoxic activity of two fractions (EdPh and EdPh-B) as well as the two isolated flavonoids (3 and 4) against two cancer (OVK-18 and MCF-7) and a normal (NHDF) cell lines was evaluated. EdPh, EdPh-B and compound 3 showed remarkable inhibitory activities against OVK-18 with IC 50 values 3.21, 5.10 μg/mL and 10.35 µM, and MCF-7 with IC 50 of 25.29, 6.09 μg/mL and 15.17 µM, respectively compared to vinblastine as a positive control. [ABSTRACT FROM AUTHOR]